1. Field of the Invention
The present invention relates to flexible flail trimmers for trimming grass and weeds and for edging lawns, and more particularly to guiding such trimmers for edging and for guarding against thrown debris.
2. Description of the Prior Art
Flexible flail trimmers have become very popular. While initially used for trimming grass and weeds around trees, shrubs, fences and the like, they are now being used for many applications including the "edging" of sidewalks and curbs. This use serves a dual purpose. First, it eliminates the need for an additional piece of lawn care equipment, namely, a conventional rollable rotating blade edger. Secondly, it enables lawn care maintenance workers to trim around trees, shrubs and the like and to edge sidewalks and curbs without having to change equipment between operations. In other words, the flexible flail trimmer is becoming an "all-in-one" lawn care tool.
Nevertheless, the typical flexible flail trimmer is generally ill-suited for accurately edging along sidewalks and curbs where an edge line must follow and conform to the edge of the adjoining pavement or the like. When the turf edge produced by the edger is wavy or non-uniform, the finished appearance of the turf/pavement junction looks sloppy and is unacceptable.
To edge a sidewalk with a conventional flexible flail trimmer, a user must orient the plane defined by the rotating flail generally both vertically and perpendicularly to the sidewalk. The user must then walk down the sidewalk, advancing the trimmer while maintaining the vertical rotating flail plane generally co-planar with the vertical pavement surface of the sidewalk edge (proper horizontal orientation), and at the same time holding the disposition of the rotating flail tip generally adjacent the horizontal sidewalk surface at the sidewalk edge (proper vertical orientation). Most individuals lack the acute manual dexterity and eye-hand coordination necessary in order to successfully maintain these parameters to yield a uniform lawn edge, of proper depth, and at the sidewalk edge. The possible errors are compounded, of course, by the distance of the cutting flail from the position of the user's hands on the handle, the relationship of his hands or other handle support to each other, the overall balance of the trimmer, and the like.
In addition, using a flexible flail line trimmer in this manner can be dangerous for the user. The debris shields associated with traditional flail trimmers have not been designed nor installed with this use in mind. For example, many flexible flail trimmers have shields which provide less than 360 degree circumferential coverage. When these types of trimmers are turned or oriented for use as an edger, the unshielded portion of the flail path is frequently directed towards the user. Also, many commercial lawn care workers simply remove the guard or shield altogether so as to better manipulate the trimmer during edging of sidewalks, leaving the entire circumference of the trimmer exposed.
Furthermore, it is extremely fatiguing for a user to stoop over and walk forwardly while attempting to maintain precise and accurate placement of the trimmer head while suspending it above the ground surface. This car easily lead to lower back strain.
Numerous devices have been proposed to address these difficulties. Many of these provide means for rolling a flexible flail trimmer along a curb or sidewalk to edge the grass adjacent thereto. Generally, these types of devices have some sort of bolt-on wheel arrangement wherein a flexible flail trimmer may be converted to a lawn edger. Such a combination effectively provides a user with physical feedback in a vertical plane, thereby eliminating the need to manually suspend the trimmer cutting head above the lawn while in a stooped position and hence ridding a user of low-back strain. Such devices are disclosed, for example, in U.S. Pat. Nos. 4,914,899; 4,803,831; 4,756,148; 4,712,363; 4,679,385; 4,442,659; 4,224,784 and 3,788,049. These add-on devices, however, are generally cumbersome, expensive, and may in fact adversely effect the trimming operation of the trimmer when used in the traditional trimming manner.
Another flexible flail edging device is disclosed in U.S. Pat. No. 4,268,964. This device eliminates the bolt-on wheel arrangement for converting a flexible flail trimmer into a lawn edger. It instead utilizes a disk as a means for rollably supporting the trimmer against the horizontal sidewalk surface. This device has several advantages in that it eliminates the need for a bolt-on wheel arrangement, utilizes existing structure for rotatably supporting the flexible flail trimmer, and does not inhibit normal trimming of grass and weeds around trees, shrubs and the like, since the flail extends outwardly from the disk.
Nonetheless, this apparatus for trimming and edging has several inherent problems. First, since the rotating shield or disc is outboard of the cutting head, the shield does not provide the user with any protection from airborne debris generated by the action of the cutting head, and the flail tips are not enclosed. While the shield may protect the rotating structure from hitting stones or other objects that might damage the rotating structure during conventional trimming, the cutting head is open to the user and could propel debris or objects in his direction.
In addition, this device has no means by which a user may guide the flexible flail trimmer in a straight line along a sidewalk or curb. While it does support the flail above the walk, there is no guidance or physical feedback in the horizontal direction. Accordingly, the uniformity of a turf edge obtainable by a user is limited by the manual dexterity and eye-hand coordination of the user. This device, while eliminating user lower back strain and providing a uniform depth of turf cut, does nothing towards aiding a user in delivering a uniform turf cut or edge parallel to or uniformly spaced from the sidewalk edge, which is the most important aesthetic aspect of sidewalk edging.
It has therefore been one object of the present invention to provide an improved flexible flail trimmer which can be used for cutting and trimming grass and weeds around trees, shrubs and the like and which also facilitates edging lawns positively and uniformly along sidewalks and curbs.
Another object of the present invention is to provide a combination flexible flail trimmer and lawn edger wherein the user is shielded effectively from airborne debris generated by the cutting head during any use.
Yet another object of the present invention has been to provide a flexible flail trimmer which can not only be used for cutting and trimming of vegetation around trees, shrubs, fences and the like but which may also be used for uniformly edging lawns along sidewalks and curbs without the need for adding accessory wheels or guide apparatus.
Yet a further object of the present invention has been to combine the capability of cutting and trimming of vegetation with uniform edging of sidewalks and curbs in a single apparatus.
Still a further object of the present invention has been to provide a flexible flail trimmer which, when operated as a lawn edger, will provide an aesthetically pleasing turf cut which uniformly tracks a sidewalk edge, whether straight or curved.
A further object of the present invention has been to provide apparatus for converting a flexible flail trimmer into a lawn edger for uniformly edging a lawn, while at the same time protecting a user from thrown debris and while retaining the trimming function of the apparatus.